Ripley in Alien films - I was always asking why the hell she always needed to be involved when the Aliens could terrorise someone else?
I don't feel that way with Terminator - there are many of him and he's like the backbone of Skynet's Terminator units - T1000 was a prototype as was the TX. The previous series' were discontinued (400 series, etc).
Just made more sense he was always around.
Now, I like that they've pulled the rug by invading the timelines of film 1.
This links it better than T3 or TS IMO.
As far as I can tell it has been done faithfully and with thought - Sarah protected by a Terminator for decades, now with its human tissue aged, it knows what will happen as it was sent with this knowledge AFTER the Termintor in T1 was sent back.
How does it know exactly WHERE the first Terminator arrives or where Reese does? We'll have to see. How could the resistance send him to protect the young Sarah?
I am also intrigued as to how a T1000 came to be there - maybe a contingency to try again after Skynet knew the 1984 terminator failed?
Whew....